Environmentalists are urging US Harry Potter fans to buy copies of book six from Canada, where it is being printed on recycled paper.
The sixth Harry Potter book will be be published worldwide on 16 July
Harry Potter and the Half-Blood Prince is published worldwide on 16 July, with a recycled version issued by Canadian publisher Raincoast Books.
Vancouver conservation group Markets Initiative said US publisher Scholastic rejected a plea to use recycled paper.
But Scholastic has said it does not use paper from endangered forests.
US retailers are predicting record sales of the new book after the fifth instalment sold more than five million copies on its first day in June 2003.
Markets Initiative urged US fans to buy the book online from Raincoast Books, which also published a recycled version of Harry Potter and the Order of the Phoenix.
"Scholastic has failed to really meaningfully step forward to have Harry printed on the most environmentally friendly paper that it can be," Markets Initiative spokeswoman Nicole Rycroft told the New York Times.
Scholastic told the paper it did use some recycled paper for its books, including the Potter series, but did not reveal how much.
Scholastic spokesperson Kyle Good said the company was committed to using only paper that did not come from ancient or endangered forests.
"I think the fans who know Scholastic and the people who buy from Scholastic understand that we are an environmentally concerned company and we don't endanger forests ever with the paper we use," she said.
Harry Potter and the Half-Blood Prince's UK publisher Bloomsbury declined to comment.